As integrated circuits increase in speed, the necessity to remove heat from these devices becomes increasingly important to assure proper operation. The use of heat sinks to dissipate heat from integrated circuits is well known, however, as advances in semiconductor technology results in increased speed and reduced chip size, the problems associated with the use of heat sinks can compound.
For example, one trend with modern integrated circuits is to use multi-chip modules. Multi-chip modules (MCM) attach multiple integrated circuits to a single substrate in order to save space and allow for user upgrades. One solution for dissipating heat from a MCM has been to attach heat sinks using an epoxy based adhesive. A problem with the use of epoxy based adhesives is that the permanent characteristics of the epoxy limit traceability of individual integrated circuits by lot markings on the top of the device. As a result, the tracking of failures and failure mechanisms in the production of MCMs products becomes difficult.
Another problem with the use of epoxy based methods is that the use of such adhesive processes is costly, specifically because of long oven cure times. Generally, 2 to 24 of cure time is needed to attach a heat sink to a integrated circuit when using an epoxy based adhesive.
Yet another problem associated with the use of epoxy attach methods is the mismatch of thermal coefficients of expansions (TCE) between the heat sink, the integrated circuit, and the underlying substrate. As a result of the mismatched TCEs, it is possible for a heat sink or integrated circuit to delaminate from the epoxy/glue.
Therefore, it would be desirable to identify a method and apparatus that overcomes these problems.